Submarine cable loading coil



Aug. 29, 1933 Q E, BUCKLEY 1,9243% SUBMARINE CABLE LOADING COIL Filed July 25, 1930 INVENTUR U. E; EUCKL EY M J ATTORNEY SUBMARINE CABLE LOADING 0011.

Oliver E. Buckley, Maplewood; N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a Corporation'of New York Application .July 25, 1930. Serial No.'470,648 3 Claims. (01. 178-46) The present invention relates to. lump loaded submarine signaling cables and particularly to the construction of the loading coil housings customarily used in such cables; 1

An object of the invention is to protect the loading coils of submarine signaling cables from mechanical injury without decreasing the efliciency of signal transmission over such cables.

A further object of the invention is to provide a loading coil housing which will permit easy and convenient assembly. 1

It has heretofore been proposed to enclose submarine cable loading coils in metallic envelopes or housings. When signaling currents are transmitted over loaded cables the loading coils of which are provided With such housings, eddy cur-,

rents are generated in the metallic housing and a considerable loss of signaling energy ensues.

These losses are particularly troublesome when.

loading coils with windings of thesolenoidal'type r are used, since'these coils have an external field of considerable intensity.

In accordance with the presentinvention, this" loss is eliminated or at least minimized to such an extent as to render'possible the transmission of voice currents over considerable distances, by providing non-magnetic gaps in the body of the housings, such as rectangular, or otherwise shaped openings or slots. In order to further re-v duce the tendency to the formation of eddy currents, these openings or slots are arranged in staggered formation.

In the accompanying drawing which shows one embodiment of the present invention:

Fig. 1 represents a longitudinal section through a loadingcoil housing, the core of magnetic material and the surrounding winding being shown in elevation; 1 I

Fig. 2 'represents a View in elevation of a loading coil housing in accordance with the invention when applied to a submarine cable of the.

twin core type.

In Fig. 1 the elongated core of magnetic material 10 is surrounded by an insulated winding 11 which is welded or otherwise securely connected to the conductor 12 as shown. The cable insu-- 'ment of the invention. 7

action between them and the loading coil hous- 5:;

ing; v

Fig. 2 represents an elevational view of a loading coil housing in accordance with the invention. The gaps 16 are staggered, as shown. This figure furthermore shows a method of in- 2 serting the loading coil housing into a cable of the twin conductor type.

The return conductor 18 may be terminated short of the loading coil and the sea water and armor wires relied upon the copper return conductor 18 may be connected to the protective housing in the manner shown. A material which is particularly suitable as a housing in accordance with this inventionis cop-- per or, copper-clad steel; on account of the corrosion resistance of copper when submerged in sea water, and its high conductivity.

,In order to permit easy application of the housing to the combination of coil and adjacent cable core, it is made in two parts, divided either longi' tudinally or transversely.

Inthe embodiment described the housing isfi divided longitudinally along line'AB (Fig. 2).1" For the purpose of preventing longitudinal or .transverse displacements of one half of the which fit into four correspondingslots 20 of the other half. Sufficient clamping action is exerted by, the armor to assure tight contact between the shell halves and to obviate the provision of special clamping means inthis particular embodi- I 3. A submarine cable including a'loading coil comprising a case and having an external mag netic field, said coil and case being adapted to minimize energy losses due to the flow of signaling currents in said coil, said coil comprising a core of magnetic material and a winding surjf rounding said core, the insulation and fabriccovering of the cable being continued over and surrounding said Winding, said case consisting of a material having a tensile strength higher than that of ordinary highly permeable magnetic iron and being split longitudinally into a plurality 

